1. Field of the Invention
The present invention relates to a display device and a driving method thereof. More particularly, the present invention relates to a display device including an organic light emitting diode (OLED) and a pixel that is digitally driven, and a driving method thereof.
2. Description of the Related Art
Recently, a display panel has increased in size and reduced in weight, and a stable driving method of a frame has been developed in order to display an accurate and clear image with high-integration and high-precision of a display device which is required to implement a 3D stereoscopic image.
An analog-type driving method of a conventional display device increases the number of circuit elements in a pixel so that it cannot be applied to a large-sized panel, and causes problems in high-resolution display panel, particularly, FULL HD panel. A conventional pixel circuit is formed of 7 to 8 transistors and 2 to 3 capacitors, and this becomes a difficulty in layout design and manufacturing of the display panel.
In order to solve such a problem, a digital driving method replaces the analog driving method and high integration and high resolution can be realized by reducing the number of circuits in a pixel. In particular, in the pixel employing the digital driving method can be formed of 2 to 3 transistors and 1 capacitor so that the difficulty in layout design and manufacturing of the display panel can be solved.
However, a driving transistor transmitting a driving current according to a data signal is operated in a linear area in the digitally driven pixel, and thus luminance is not uniform in the entire panel depending on a material of an organic light emitting diode and a distribution characteristic such as processing. Thus, a failure such as long range uniformity (LRU) or a short range uniformity (SRU) occurs in the display panel, thereby causing deterioration of the display device.
Accordingly, development and research for a pixel structure having high integration and high resolution adaptability in the digital driving method while having a screen display characteristic of the conventional analog driving method, and a display device including the same and a driving method thereof are required.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.